Students view pictures of the Teton Dam and watch a video about the purpose of reservoirs. Students learn about and discuss the Teton Dam collapse of 1976.

Lesson Summary

Students view pictures of the Teton Dam and watch a video about the purpose of reservoirs. Students learn about and discuss the Teton Dam collapse of 1976.

This lesson is part of Great States: Idaho | Unit 9: Industry, Economy & Government which explores the interconnections of Industry, Economy, & Government. A particular emphasis will be placed on undertakings that bring all three of these forces together such as resource extraction and infrastructure development.

Time Allotment

20 minutes

Learning Objectives

Standards:

Goal 4.SS.2.2: Explain how human actions modify the physical environment and how physical systems affect human activity and living conditions.

Supplemental Standards:

Boise District 413.33: Identify ways the land in Idaho has been changed by people, technology, and natural forces.

Boise District 413.41: Explain how machines and technology have affected the natural resources of Idaho.

Supplies

A smart board, projector, or other type of screen to show videos to the class

Directions

Project image of the Teton Dam Collapse.Explain to students that in 1975 they built the Teton Dam in southeastern Idaho in the valley of the Teton River. Point out the manmade earthen dam that extends across the river. People changed the environment by building the dam, which was built to control flooding in the region and to provide a source of drinking water and hydropower, which is power, such as electricity, derived from the energy of water. The earthen dam was 310 feet high and .6 miles long; an earthen dam means it is built out of soil and rock as opposed to concrete or manmade materials. The dam was completed in November of 1975, and they began to fill the dam’s reservoir with a little bit of water each day.

Point out the right side of the dam, where the dam should have extended the length of the river, but instead the water is flowing through. On the morning of June 5, 1976, during this slow process of the dam’s reservoir being filled with water, a leak formed. Workers attempted to close the leak but quickly had to evacuate the area as the dam continued to erode and collapse. By that evening on June 5, the reservoir had completely emptied into the canyon and flooded several communities immediately downstream.

Play the video, Water | Science Trek up to 1:00, which talks about reservoirs and shows live footage of the Teton Dam collapse.It happens so quickly that the collapse segment can be shown to the students twice [0:49-1:00]. Note to students how much water and how fast it’s flowing.

The flood, which brought sediment, trees, debris, and houses along with it, damaged and destroyed many homes and businesses. Sadly, 11 people died as a result, as did thousands of cattle. Ecological habitats were also affected; banks of the river and key plants were washed away. Native fish populations were negatively affected as their habitats were inundated with sediment and debris. The attempted construction and eventual collapse of the manmade Teton Dam resulted in an ecologically disastrous, fatal catastrophe.

Unfortunately, previous warning signs of danger were ignored: geologists warned that the area was seismically active—or prone to earthquakes. Large fissures or crevices in the ground were found not far from the dam’s location. But the dam construction had continued regardless.

Discuss with students if they think that building the dam was a good idea given the warning signs. The study of the cause of the collapse was controversial, but it has been determined that it was due to a combination of deep cracks or fissures in the rocks surrounding the dam as well as the type of soil used in the dam’s core, which had also cracked. Water probably seeped in the cracks and eroded the dam internally, which eventually led to the fatal Teton Dam failure.

The collapse of the Teton Dam led the Bureau of Reclamation (the bureau that built the dam) to create a Dam Safety program. This allowed for the existing and future dams of Idaho and elsewhere to be better monitored for potential danger issues. While utilizing water as an energy source and for general consumption is a great thing, this is an example of how technology can go wrong—especially when people ignore key warning signs.

Project the image of the Teton Dam Remains, which shows what the area looks like today. Students can see that they did not try to rebuild the dam after collapse.